The specification of cost-optimal tolerances is ever since a major challenge for design engineers to ensure functionality as well as economic efficiency of mechanical assemblies. However, the underlying conflict "as tight as required, as wide as possible" is as old as the design, manufacturing of mechanical parts and their assembly itself – going back to times, when first plain tools were produced by hand using stones and wood. Since then, a long and challenging path has been taken by researchers and industrial experts to develop today’s effective methods and tools on tolerance engineering. In this paper a historical review on tolerance engineering of dimensional and geometrical tolerances in mechanical engineering is presented. Starting with the early beginnings during the age of individualized manufacture, four ages of tolerance engineering are analyzed and its major achievements are presented and discussed. Finally, we are looking ahead – focusing on current and upcoming trends in tolerance engineering.